[Yaesu] Re: FT-1000D 4th IF / Notch and Prod Det - Frequencies? Function?

[Chris Codella, W2PA]

Last installment. 

The output of the 4th IF amp goes to both the AM detector, D2060, 
co-located on the IF Unit, and to the SSB detector, D3005, located on 
the Audio Unit.  The SSB detector is also getting a BFO signal from 
Q3006, which is derived from the 12.280/283 MHz signal coming from 
Q2056/Q2055, through buffer Q2056, then mixed in Q3004 with the 12.18 
MHz signal coming from Q3002/3003.

I think.  (It's getting late.)

Both detectors feed into audio filter op-amps on the Audio Unit.  There 
are separate ones for SSB (Q3016-1), AM (Q3015-1), CW (Q3015-2), and CW 
with APF (Q3016-2), switched in and out by quad-switch Q3017.  From here 
the audio finds its way to one of several outputs, combined with sub-RX, 
monitor, etc.

73,
Chris, W2PA


KA9S - Jeff wrote:

>I would like to understand the frequency scheme of the 4th mixer, 4th 
>IF / notch filter, and product detector of my FT-1000D. I would also 
>like to know how these stages function. 
>